Soluble Functionalised Carbon Nanotubes Used as Building Blocks of Electronic Nanostructures

J. BALACH; D.F. ACEVEDO; M.C. MIRAS; C.A. BARBERO

Viña del Mar, Chile

Workshop; Frontiers In Materials research III. International Workshop; 2008

Carbon nanotubes are interesting materials to be used as components of electronic devices such as transistors. While it is possible that some carbon nanotube devices could compete with silicon based devices (e.g. power transistors), it is more likely that wet processing of carbon nanotubes will allow producing simple devices of technological interest. Pristine carbon nanotubes have low solubility due to weak interaction with solvent molecules and strong p-p and dispersive interaction between individual nanotubes. Therefore, the required solubility could be achieved by attachment of functional groups which interact efficiently with solvents and, due to steric effects, decrease the interaction between neighbouring nanotubes. In the present communication, different approaches of nanotube functionalisation are presented: covalent bonding of functional groups and non covalent interaction. The first approach is made by reaction of the aromatic ring with aryl cations or formaction of acyl derivatives. The later is made by adsorption of soluble polyanilines or polynuclear aromatic molecules. The polyanilines are produced by combinatorially selected chemical reactions on the polyaniline backbone. The aromatic compounds are produced by diazonium coupling of aromatic amines and activated aromatic rings (phenols, amines, polynuclear). The compounds are tested by high throughput screening in terms of their ability to solubilize multiwall carbon nanotubes (MWNT). The functionalised nanotubes are then used to build electronic nanostructures, such as layer-by-layer self assembled multilayers made of functionalized nanotubes together with polyelectrolytes (including conducting polyelectrolytes). The mechanism of charge transfer between layers is probed by dynamic electrochemical techniques and electrocatalytic reactions